Figure 6. Purified aPL, as well as APS patient plasma, stimulate thrombin generation in neutrophil- and DNA-dependent fashion.

A, Representative thrombin (IIa) generation plot demonstrating enhanced generation when neutrophils are exposed to platelet-poor plasma (from a healthy control) supplemented with aPL CL1 (10 μg/ml). The effect is not seen with plasma alone or plasma supplemented with control IgG. The effect is disrupted by DNase treatment. B, Representative data demonstrating that control plasma supplemented with anti-β₂GPI monoclonals promotes neutrophil-mediated thrombin generation. Delta (Δ) values were calculated relative to the baseline condition (in this case, plasma supplement with IgG, but not neutrophils). These data are representative of 3 experiments, all with similar results. C, Control plasma was separately supplemented with total IgG (10 μg/ml) isolated from 5 healthy controls or 5 primary APS patients with anti-β₂GPI IgG positivity. Plasma was then mixed with control neutrophils alone or neutrophils + DNase, and thrombin generation was determined. D, Plasma from healthy controls or primary APS patients was mixed with control neutrophils alone or neutrophils + DNase, and thrombin generation was determined. In panels C and D, mean and standard deviation are presented; *p<0.05 and **p<0.01. Each data point is the average of 3 independent assays.